848
FXUS65 KBYZ 070648
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
1248 AM MDT WED OCT 7 2026
KEY MESSAGES
- VERY WARM, DRY AND OCCASIONALLY BREEZY THROUGH FRIDAY. FIRE
CONCERNS WILL REMAIN ELEVATED, AND MAY BE CRITICAL ON FRIDAY
WITH INCREASED WINDS AND LOWER HUMIDITIES.
- COLD FRONT ARRIVES EARLY SATURDAY, THEN MUCH COOLER SATURDAY
NIGHT THROUGH TUESDAY; THIS WILL BE THE COOLEST AIR MASS YET OF
THE FALL.
- STRONG WEATHER SYSTEM ARRIVES THIS WEEKEND. INCREASING
CONFIDENCE FOR MOUNTAINS/FOOTHILLS SNOW SATURDAY NIGHT TO
MONDAY, WITH RAIN AND WET SNOW AT LOWER ELEVATIONS. GREATEST
POTENTIAL FOR SNOW ACCUMULATIONS IS OVER MOUNTAINS AND FOOTHILLS
WEST OF BILLINGS. POTENTIAL IMPACTS TO TRAVEL AND OUTDOOR
RECREATION. DETAILS REMAIN VERY UNCERTAIN.
DISCUSSION
THROUGH NEXT TUESDAY...
THE NEXT 7 DAYS IS A TALE OF TWO WEATHER REGIMES.
TODAY THROUGH FRIDAY WILL REMAIN QUITE WARM & DRY AS FLAT RIDGING
WITH ABOVE NORMAL HEIGHTS DOMINATES THE NORTHERN ROCKIES AND HIGH
PLAINS. THERE IS A WEAK COLD FRONT DROPPING OUT OF CANADA THIS
MORNING THAT WILL SHIFT WINDS TO THE NE-E AND PROVIDE A BIT OF
BACKDOOR COOLING, ALONG WITH HIGHER HUMIDITIES. THURSDAY IS
LOOKING A LITTLE WARMER & DRIER AS EAST WINDS SLACKEN. FRIDAY IS
OF GREATER CONCERN WITH REGARD TO FIRE WEATHER AS SW FLOW
AMPLIFIES AND DOWNSLOPE WINDS/WARMING BECOME ENHANCED AHEAD OF AN
APPROACHING CANADIAN FRONT. WESTERN FOOTHILLS SHOULD SEE GUSTS TO
40 MPH ALONG WITH RHS AS LOW AS THE SINGLE DIGITS TO LOWER TEENS,
AND TEMPS BACK TO THE 80S. ONE BENEFICIAL ITEM OF NOTE IS THAT THE
FROPA ITSELF WON'T ARRIVE UNTIL EARLY SATURDAY, SO SHIFTING/
FRONTAL WINDS WILL NOT BE AN ISSUE IN OUR AREA ON FRIDAY. THERE
MAY, HOWEVER, BE MODEST MOUNTAIN WAVE POTENTIAL IN THE LEE OF THE
BEARTOOTHS & BIGHORNS EARLY SATURDAY. MODEL SOUNDINGS SHOW ONLY A
VAGUE SIGNAL FOR MOUNTAIN WAVES BUT THIS IS SOMETHING TO KEEP AN
EYE ON.
COLD FRONT SATURDAY MORNING WILL BRING A SHIFT TO BRISK N-NE WINDS
AND COOLING THRU THE DAY. THE COOLING WILL BE NOTICEABLE. AT THE
SAME TIME, A POTENT UPPER LOW WILL DROP FROM BC TO THE PACNW.
SHOWER CHANCES WILL INCREASE OVER THE WEST DURING THE DAY, BUT THE
MAIN SHOW LOOKS TO BEGIN SATURDAY NIGHT AS LARGE SCALE ASCENT AND
DEEPENING UPSLOPE FLOW COMBINE WITH FALLING TEMPS TO BRING A RISK
OF FOOTHILLS AND LOWER ELEVATION SNOW FOR THE FIRST TIME THIS
FALL.
THERE REMAINS PLENTY OF UNCERTAINTY WITH THIS SYSTEM, WHICH IS
EXPECTED TO IMPACT US IN SOME FASHION FROM SATURDAY NIGHT THROUGH
MONDAY, AND PERHAPS A BIT LONGER. HIGH CONFIDENCE EXISTS FOR MUCH
COOLER TEMPS (HIGHS IN 30S & 40S SUNDAY & MONDAY) AND A HEALTHY
DOSE OF PRECIPITATION (WHICH SHOULD FEATURE MOUNTAINS AND WESTERN
FOOTHILLS SNOWFALL). MID LEVEL E-SE WINDS FAVOR WESTERN FOOTHILLS
FOR GREATEST PRECIPITATION POTENTIAL. HIGH UNCERTAINTY EXISTS WITH
EXACT TRACK OF THE LOW AND MAGNITUDE OF PRECIPITATION WE WILL
SEE, IN ADDITION TO SURFACE TEMPS AND HOW MUCH SNOW WILL BE ABLE
TO ACCUMULATE AFTER A STRETCH OF VERY WARM WEATHER. ONE THING
NOTED IN TODAY'S MODELS WAS A LINGERING WEAK SPLIT TROF OVER
WESTERN MT THROUGH MONDAY, WHICH IS IMPORTANT AS IT SUGGESTS THE
LOW WILL NOT YET BE COMPLETELY CUT OFF TO OUR SOUTH, KEEPS ASCENT
GOING AND COOLER AIR IN PLACE. FOR THESE REASONS CONFIDENCE IN
ACCUMULATING SNOWFALL IS A LITTLE HIGHER NOW THAN IT WAS
YESTERDAY.
SPEAKING OF CONFIDENCE HERE ARE SOME CURRENT PROBABILITIES. THE
CHANCE OF 1+ INCHES OF SNOW IS 10% OVER THE EAST, 40% AT BILLINGS
AND 70-80% ALONG WESTERN FOOTHILLS. THE CHANCE OF 6+ INCHES OF
SNOW IS NON-ZERO AT BILLINGS (10%) AND 35-45% ALONG THE WESTERN
FOOTHILLS. WESTERN MOUNTAINS WILL OF COURSE SEE MORE SNOW THAN
THIS. PER ENSEMBLES, PRECIP IS EXPECTED TO BE NEAR AN INCH IN OUR
WEST TAPERING TO A HALF INCH CENTRAL PARTS AND NEAR 0.15" IN THE
EAST. OF COURSE, THIS IS SUBJECT TO CHANGE. IF ASCENT AND UPSLOPE
WINDS REMAIN FAVORABLE THROUGH MUCH OF MONDAY, AND IF MOISTURE
FROM REMNANTS OF HURRICANE RACHEL BECOME INVOLVED, WE MAY BE
LOOKING AT SIGNIFICANT ACCUMULATING WET SNOWFALL ACROSS WESTERN
FOOTHILLS. POTENTIAL IMPACTS INCLUDE TRAVEL AND WEIGHTED DOWN
LEAFY TREES. ALSO, IT IS LIKELY THAT MOST OF THE REGION SEES ITS
FIRST FREEZE OF THE FALL. PLEASE MONITOR THE FORECAST IF YOU ARE
PLANNING TO TRAVEL OR ENGAGE IN OUTDOOR ACTIVITIES SATURDAY NIGHT
THROUGH MONDAY.
LIGHT PRECIP MAY LINGER THROUGH MONDAY NIGHT INTO EARLY TUESDAY,
BUT OVERALL TUESDAY SHOULD BEGIN THE TREND BACK TO WARMER AND
DRIER. LOOK FOR HIGHS IN THE MID 40S TO MID 50S.
JKL
AVIATION
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. WINDS WILL
SHIFT OUT OF THE NORTHEAST TO EAST ACROSS MUCH OF THE AREA BY THIS
AFTERNOON. ARCHER
PRELIMINARY POINT TEMP/POPS
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 075 045/079 049/084 052/065 036/042 030/041 031/052
0/U 00/U 00/N 01/B 79/W 84/W 32/W
LVM 079 041/079 043/082 046/065 030/041 023/044 024/051
0/U 00/U 00/N 05/W 89/W 84/W 32/W
HDN 076 039/078 043/087 049/069 037/046 031/045 029/054
0/B 00/U 00/U 01/B 78/W 74/W 32/W
MLS 072 043/074 047/082 050/068 040/048 036/045 035/052
0/B 00/U 00/U 00/B 57/W 74/W 22/W
4BQ 076 044/077 049/086 053/074 041/051 037/048 036/053
0/B 00/U 00/U 00/U 45/W 74/W 33/W
BHK 073 039/075 044/085 049/075 037/051 032/047 029/052
0/B 00/U 00/U 00/U 36/W 85/W 32/W
SHR 078 040/079 042/086 048/072 035/049 030/047 029/054
0/U 00/U 00/U 01/B 67/W 84/W 44/W
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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